There is continuously-growing concern about improvements in high-efficiency power production technology so as to improve the utility of existing energy sources and efficiency of power demand and supply. As an alternative for improving high-efficiency power production technology, research and development for a regenerative Brayton cycle have been briskly carried out.
However, in the conventional regenerative Brayton cycle, a working fluid introduced into a heater is heated using a heat source, such as a combustion gas discharged from a turbine, etc. Nevertheless, there is a problem that waste heat is not sufficiently used and is discarded.